A favorite for MBC in Legacy. Killing it is bad, not killing it is worse; especially since any deck running him is loaded with sac effects, most of which are uncounterable.

He's huge, he beats you up badly, he's immune to Doom Blade, Dismember, and Smother; among burn and a host of other spells. He has a drawback that your opponent might play into if they think they're being tricky (usually they're not) and he's beautifully crafted as not only Timmy, but as demonic (sacrifice for power!) and the drawback actually matters a bit more when you realize you have certain deck catering decisions to be making.